During vehicle motion along a curve, inertia causes the mass of the vehicle to continue in a straight line, away from the direction of the curve, causing the body of the vehicle to sway. This sway, or redistribution of weight, causes compressive force to be applied to the control arm furthest removed from the center of the curve, (i.e. the outer control arm), and expansive force on the control arm nearest the center of the curve, (i.e. the inner control arm).
A stabilizer or sway bar links the inner and outer control arms. During vehicle sway, the stabilizer bar experiences upward movement due to the expansive force applied to the inner control arm and experiences downward movement due to the compressive force applied to the outer control arm, causing axial rotation. The presence of the stabilizer bar lessens the rotational or sway motion of the vehicle frame.